Synthesis of atomically thin yellow pearl: An impetus for nonlinear optical effect assisted light scattering application

Synthesis of 2D materials from natural resources, and having unique functionalities have created enormous research interest among material scientists. Such 2D materials can be used as impetus for light scattering to generate continuous wave (CW) pumped random laser (RL) emission at room temperature. In this work, defects-free 2D yellow pearl (2D-YP) has been synthesized from bulk south sea pearl using liquid-phase exfoliation (LPE) technique. Thereafter, 2D-YP has been employed as a passive scatterer to achieve CW pumped RL emission from a conventional gain molecule. Compared to other semiconductor (TiO<inf>2</inf>) and 2D (Graphene and hBN) passive scatterers, ∼25 times improvement in gain volume is observed for the disordered system consisting of 2D-YP, and is due to the formation of a large refractive index gradient via thermal nonlinear optical (NLO) interaction. Hence, incoherent RL (ic-RL) emission ∼591 nm is reported at a lowest threshold input pump power and a linewidth of 65 mW and 3 nm, respectively. Additionaly, a clear transition from ic-RL to mode tunable coherent RL (c-RL) emission is also demonstrated by altering the pump configuration. Therefore, the newly designed van der Waals heterostructure, i.e., 2D-YP with intrinsic photon trapping capability may pave an avenue towards developing exciting optoelectronic devices.